<?php
$score = 85;

// if-else语句
if ($score >= 90) {
    echo "优秀\n";
} elseif ($score >= 80) {
    echo "良好\n";
} elseif ($score >= 60) {
    echo "及格\n";
} else {
    echo "不及格\n";
}

// switch语句
$day = "星期一";
switch ($day) {
    case "星期一":
        echo "Monday\n";
        break;
    case "星期二":
        echo "Tuesday\n";
        break;
    default:
        echo "其他日子\n";
}
?>